Patents by Inventor Tomoko Ohtsuki

Tomoko Ohtsuki has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7277220
    Abstract: A laser apparatus including a laser generating portion that generates pulse light having a single wavelength within a range from an infrared band to a visible band. An optical amplifier is optically connected to the laser generating portion, and includes a plurality of fiber optical amplifiers to amplify the pulse light a plurality of times. A wavelength converting portion is optically connected to the optical amplifier, and includes cylindrical lenses and a plurality of non-linear optical crystals to wavelength-convert the amplified pulse light into ultraviolet light. The amplified pulse light is incident on the cylindrical lenses through one of the plurality of non-linear optical crystals and is incident on a different one of the plurality of non-linear optical crystals from the one non-linear optical crystal through the cylindrical lenses.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: October 2, 2007
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 7212275
    Abstract: A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 ?m. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: May 1, 2007
    Assignee: Nikon Corporation
    Inventor: Tomoko Ohtsuki
  • Publication number: 20070008609
    Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.
    Type: Application
    Filed: September 13, 2006
    Publication date: January 11, 2007
    Applicant: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 7136402
    Abstract: A laser device which can be used as a light source for an exposure device, can be downsized, and is easy to maintain. A laser beam (LB6) emitted from a DFB (Distributed feedback) semiconductor laser, for example, and amplified by an optical fiber amplifier is passed through non-linear optical crystals (502, 503, 504) to be sequentially doubled in frequency to thereby generate an ultraviolet-region laser beam (LB5) consisting of an octuple wave. A GdYCOB, that is, GdxY1?xCa4O(BO3)3 crystal (0?×?1) is used for the non-linear optical crystal (503) for a double wave-to-quadruple wave conversion, and a KAB, that is, K2Al2B4O7 crystal for the non-linear optical crystal (504) for a quadruple wave-to-octuple wave conversion. The non-linear optical crystals (502-504) are all fine-tuned in phase match angle by temperature controllers (521-523) respectively.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: November 14, 2006
    Assignee: Nikon Corporation
    Inventor: Tomoko Ohtsuki
  • Patent number: 7126745
    Abstract: A method of irradiating ultraviolet light onto an object. The method includes generating pulse light having a single wavelength within a range from 1.51 ?m to 1.59 ?m from a laser generating portion, amplifying the pulse light plural times with an optical amplifier that includes a plurality of fiber optical amplifiers, wavelength-converting the amplified pulse light into ultraviolet light with a wavelength converting portion that includes a plurality of non-linear optical crystals, and irradiating the ultraviolet light onto the object through an optical system.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: October 24, 2006
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 7098992
    Abstract: The light source unit includes a single wavelength oscillation light source, a light generating portion which has an optical modulator converting and emitting light from the light source into a pulse light, a light amplifying portion made up of an optical fiber group in which each fiber has a fiber amplifier to amplify the pulse light from the optical modulator, and a light amount controller. The light amount controller performs a step-by-step light amount control by individually turning on/off the light output of each fiber making up the optical fiber group, and a light amount control of controlling at least either of the frequency or the peak power of the emitted pulse light of the optical modulator.
    Type: Grant
    Filed: July 15, 2003
    Date of Patent: August 29, 2006
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa, Niichi Atsumi, Masaaki Doi
  • Publication number: 20060098269
    Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.
    Type: Application
    Filed: December 22, 2005
    Publication date: May 11, 2006
    Applicant: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 7023610
    Abstract: An ultraviolet laser apparatus having a single-wavelength oscillating laser generating laser light between an infrared band and a visible band, an optical amplifier for amplifying the laser light, and a wavelength converting portion converting the amplified laser light into ultraviolet light using a non-linear optical crystal. An exposure apparatus transfers a pattern image of a mask onto a substrate and includes a light source having a laser apparatus emitting laser light having a single wavelength, a first fiber optical amplifier for amplifying the laser light, a light dividing device for dividing or branching the amplified laser light into plural lights, and second fiber optical amplifiers for amplifying the plural divided or branched lights, respectively, and a transmission optical system for transmitting the laser light emitted from the light source to the exposure apparatus.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: April 4, 2006
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Publication number: 20060028712
    Abstract: A system, method and computer program product for determining excited state absorption (ESA) dependent parameters (gain and noise figure) of an EDF and an EDFA corresponding to a determined average inversion value of an EDF. Also, a system, method and computer program product for using an EDFA model that incorporates ESA parameters to in calculating an EDFA gain and noise figure to design laser systems with high accuracy.
    Type: Application
    Filed: May 9, 2005
    Publication date: February 9, 2006
    Applicants: FURUKAWA AMERICA, INC, OFS FITEL, LLC
    Inventors: Tomoko Ohtsuki, Jutarou Miura, Masaru Fukushima, Baishi Wang
  • Patent number: 6947123
    Abstract: An exposure apparatus has a light source comprising a laser device that is small and easy to maintain. The laser device comprises a laser oscillator for generating a single-wavelength laser beam (LB3) within a wavelength range including infrared and visible regions; an optical amplifier (18) for amplifying a laser beam (LB3); and a wavelength converter for converting the amplified laser beam into ultraviolet light using a nonlinear optical crystal. The optical amplifier (18) includes a plurality of stages of optical fiber amplifiers (22, 25) for sequential amplification of the laser beam (LB3), and a narrow-band filter (24A) and an isolator (IS3) arranged between optical fiber amplifiers.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: September 20, 2005
    Assignee: Nikon Corporation
    Inventor: Tomoko Ohtsuki
  • Publication number: 20050185683
    Abstract: A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 ?m. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.
    Type: Application
    Filed: April 22, 2005
    Publication date: August 25, 2005
    Applicant: NIKON CORPORATION
    Inventor: Tomoko Ohtsuki
  • Patent number: 6901090
    Abstract: An exposure apparatus has a laser device that is small, easy to maintain, and capable of producing an output that is unlikely to be affected by optical surges occurring in the beginning of operation. A single-wavelength laser oscillator (11) supplies a laser beam (LB1) to a fiber optic amplifier (13) through an optical modulator (12). The amplified laser beam is split by splitters (14, 16-1 to 16-m), amplified by optical amplifier units (18-1 to 18-n) and supplied through a fiber bundle (19) to a wavelength converter (20), which in turn converts the split beams into ultraviolet laser radiation (LB5) for use as exposure light. The optical modulator (12) outputs light pulses during the generation of ultraviolet light. The optical modulator (12) also produces laser radiation during the absence of ultraviolet light, but the laser radiation has substantially the same average output and a considerably low peak compared with that during the generation of ultraviolet light.
    Type: Grant
    Filed: September 8, 2000
    Date of Patent: May 31, 2005
    Assignee: Nikon Corporation
    Inventor: Tomoko Ohtsuki
  • Publication number: 20040012844
    Abstract: The light source unit (16) comprises a single wavelength oscillation light source (160A), a light generating portion (160) which has an optical modulator (160C) converting and emitting light from the light source into a pulse light, a light amplifying portion (161) made up of an optical fiber group that each has a fiber amplifier to amplify the pulse light from the optical modulator, and a light amount controller (16C). The light amount controller (16C) performs a step-by-step light amount control by individually turning on/off the light output of each fiber making up the optical fiber group, and a light amount control of controlling at least either of the frequency or the peak power of the emitted pulse light of the optical modulator.
    Type: Application
    Filed: July 15, 2003
    Publication date: January 22, 2004
    Applicant: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa, Niichi Atsumi, Masaaki Doi
  • Publication number: 20030231663
    Abstract: An ultraviolet laser apparatus according to the present invention comprises a laser generating portion having a single-wavelength oscillating laser for generating laser light having a single wavelength falling within a wavelength range from an infrared band to a visible band, an optical amplifier having a fiber optical amplifier for amplifying the laser light generated by the laser generating portion, and a wavelength converting portion for wavelength-converting the amplified laser light into ultraviolet light by using a non-linear optical crystal, whereby ultraviolet light having a single wavelength is generated.
    Type: Application
    Filed: February 19, 2003
    Publication date: December 18, 2003
    Applicant: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 6590698
    Abstract: An ultraviolet laser apparatus has a laser generating single-wavelength light between infrared and visible, a fiber optical amplifier for amplifying the laser light, and a converting portion converting the amplified laser light into single-wavelength ultraviolet light, using a non-linear optical crystal. An exposure apparatus transfers a pattern image of a mask onto a substrate and has light source including a laser apparatus for emitting laser light having a single wavelength, a first fiber optical amplifier for amplifying the laser light, a light dividing device for dividing or branching the amplified laser light into plural lights, and second fiber optical amplifiers for amplifying the plural divided or branched lights, respectively; and a transmission optical system for transmitting the laser light emitted from the light source to the exposure apparatus.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: July 8, 2003
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 6339634
    Abstract: A high-pressure krypton gas is supplied to the interior of a vessel from a gas introduction pipe. Light emitted from an optical fiber group formed by bundling together optical fibers constituting the output ends of fiber amplifiers or fiber lasers passes through a lens and exciting laser light introduction window, and is focused on the krypton gas jetting from the tip end of the nozzle. As a result, the krypton gas is excited as a plasma and soft X-rays are generated. The soft X-rays are reflected by a rotating multi-layer coat parabolic mirror and are emitted to the outside as a parallel beam of soft X-rays. Since light from fiber amplifiers is used as exciting light, and since numerous optical fibers are bundled together to form a light source, a large quantity of soft X-rays can easily be obtained.
    Type: Grant
    Filed: September 30, 1999
    Date of Patent: January 15, 2002
    Assignee: Nikon Corporation
    Inventors: Noriaki Kandaka, Hiroyuki Kondo, Soichi Owa, Tomoko Ohtsuki
  • Patent number: 6088379
    Abstract: An ultraviolet laser apparatus which generates laser light at 193 nm to 213 nm with high temporal and spatial coherence and relatively high power is disclosed. The UV laser apparatus provides a light source for an exposure device for optical lithography and an aberration measurement interferometer that measures lens wave front aberration. The laser apparatus disclosed herein comprises two lasers having laser resonators that are coincident along a portion of their respective optical paths. A nonlinear optical crystal is located along the shared optical path portion for sum frequency generation of the light of the respective lasers.
    Type: Grant
    Filed: June 9, 1998
    Date of Patent: July 11, 2000
    Assignee: Nikon Corporation
    Inventors: Soichi Owa, Tomoko Ohtsuki
  • Patent number: 6078598
    Abstract: A laser apparatus includes a laser resonator having a first reflective surface and a second reflective surface, the laser resonator further including a laser medium disposed between the first reflective surface and the second reflective surface for processing light reflected from the first and second reflective surfaces to output a laser beam to be resonated, and a resonator loss varying unit disposed between the first reflective surface and the second reflective surface of the laser resonator, the resonator loss varying unit being capable of switching a state thereof between a first state having a resonance frequency substantially coinciding with one of frequencies at which laser oscillation of the laser resonator is possible and a second state having the resonance frequency shifted to the value that is substantially different from any one of the frequencies at which laser oscillation of the laser resonator is possible to vary a loss of the laser resonator.
    Type: Grant
    Filed: April 24, 1998
    Date of Patent: June 20, 2000
    Assignee: Nikon Corporation
    Inventors: Tomoko Ohtsuki, Soichi Owa
  • Patent number: 6049558
    Abstract: Laser systems, and optical elements for laser systems, are disclosed for providing a pumped laser light with improved output efficiency while having simple construction and simple alignment adjustment. A pump light flux from a diode pumping laser irradiates and thus pumps a solid-state laser crystal. The irradiation by the pump light flux is coaxial with an output laser beam produced by the laser crystal. The pump light flux is conducted by an optical element, preferably frustoconical in shape with an entrance face larger than an exit face, that functions as a light funnel. The entrance face is disposed proximal to the pumping laser 11, and the exit face is disposed proximally to the laser crystal 14. A portion of the pump light flux entering the entrance face passes through the optical element without being reflected by a side surface of the optical element. The remaining pump light flux reflects at least once by the side surface during passage through the optical element.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: April 11, 2000
    Assignee: Nikon Corporation
    Inventors: Masaki Harada, Soichi Owa, Tomoko Ohtsuki
  • Patent number: 5329505
    Abstract: A system and method for overwriteable magento-optical recording comprises a medium having a data layer and a reference layer. The medium is heated with a laser pulse of short duration which causes a temperature gradient between the data layer and the reference layer. The temperature of the data layer becomes greater than the Curie temperature of the data layer, but the reference layer remains at a temperature below the Curie temperature of the data layer. The magnetic orientation of the reference layer thus remains unchanged and the data layer will orient itself in the same direction as the reference layer. It is therefore not necessary that the Curie temperature of the reference layer be greater than that of the data layer.
    Type: Grant
    Filed: August 18, 1993
    Date of Patent: July 12, 1994
    Assignee: IBM Corporation
    Inventor: Tomoko Ohtsuki